1. Technical Field
The present disclosure relates generally to surgical implants and to implant insertion tools and, more specifically, to cervical dowels and an insertion tool for inserting a cervical dowel into a receiving bed formed in an intervertebral space.
2. Background of Related Art
Cervical dowels and tools for inserting cervical dowels into the intervertebral space are well known in the prior art. For Example, U.S. Pat. No. 4,877,020 to which discloses a bone dowel and an instrument for inserting the bone dowel into the cervical region of the spine. The Vich dowel includes a cylindrical body, which is formed of bone extracted from the patient""siliac crest. A coil or thread is formed about the exterior surface of the dowel and the dowel is screwed into a previously prepared bed in the intervertebral space. Vich discloses a pair of instruments for inserting the dowel into the intervertebral space. A first instrument includes a pair of pins and a centrally located screw. The screw and pins penetrate one end of the dowel to secure the dowel onto a distal end of the insertion tool. Vich also discloses an insertion tool having an expandable sleeve portion which is positioned over one end of the dowel and clamped down to secure the dowel to the insertion tool.
Vich""s insertion tools are lacking in several respects. For example, Vich""s screw/pin insertion tool requires that the dowel be screwed onto the insertion tool. This makes it difficult and time consuming for a surgeon to disengage the dowel from the insertion tool. Moreover, Vich""s expandable sleeve insertion tool has a diameter larger than diameter of the dowel. Thus, it is very difficult using this insertion tool to fully insert a dowel into the intervertebral space.
Accordingly, a continuing need exists for a dowel insertion tool which can be quickly and easily attached and detached to/from a bone dowel. Moreover, a continuing need exists for an insertion tool which does not interfere with dowel insertion into the intervertebral space.
In accordance with the present disclosure, a dowel and a dowel insertion tool for inserting the dowel into the intervertebral space are provided. The implant insertion tool includes a T-shaped handle having a hollow sleeve which extends from the T-shaped handle. A shaft extends from the handle through the sleeve and includes a transverse extension. A rotatable knob having an annular channel positioned to receive the transverse extension is supported adjacent the handle. A pin is secured to the knob and extends into a helical camming channel formed in the sleeve.
Upon rotation of the knob, the pin moves within the camming channel to move the knob longitudinally about the sleeve. Movement of the knob effects longitudinal movement of the shaft. A plate is secured to the distal end of the shaft. A pair of prongs are slidably secured to the plate. Each of the prongs includes an enlarged head portion which is slidably positioned within a slot formed in the plate. A guide member is secured to the distal end of the sleeve. The guide member includes a pair of guide bores which direct the prongs away from the sleeve at an angle to the longitudinal axis of the sleeve. The prongs are dimensioned to be received in bores formed in the trailing end of a cervical dowel. Because the prongs engage the dowel at an angle, the dowel is both rotatably and longitudinally fixed to the insertion tool.